Capacitor device used in energy storage system

ABSTRACT

An energy storage system has a battery device, a first terminal, a second terminal, a capacitor device and a DC/DC converter. The first and second terminals are respectively connected two electrodes of the battery device, and the two electrodes have opposite polarities. The capacitor device is electrically connected to the first and second terminals in parallel. The DC/DC converter is electrically connected between the first terminal and the capacitor device. The battery device composed of at least one secondary battery and the capacitor device composed of at least one capacitor are electrically connected to each other in parallel, and by combining with the DC/DC converter, configuring the relation between the equivalent series resistor of the capacitor device and the internal resistor of the battery device, and/or configuring the upper current limit of the rated current of range the DC/DC converter, the battery cycle life is increased.

CROSS REFERENCE

The present invention is Continuation Application of U.S. patentapplication Ser. No. 16/832,544 filed on 2020 Mar. 27, and claimspriority of TW Patent Application 108148553 filed on 2019 Dec. 31,wherein all contents of the references which priorities are claimed bythe present invention are included in the present invention, herein.

TECHNICAL FIELD

The present disclosure relates to an energy storage system and itscapacitor device, in particular to, an energy storage system formed bycombining a battery device and a capacitor device.

RELATED ART

Handheld devices (such as notebooks, pads and phones), electric motorsand electric cars become more popular, and all of them have batteriestherein. A PCT publication, WO01/89058A1, discloses that a capacitorhaving a very low resistance of an equivalent series resistor isdisposed between a load and a battery in a circuit, and the resistanceof the equivalent series resistor must be less than a half resistance ofan internal resistor of the battery. It can be used to reduceconsumption of a transient current and a voltage drop generated on thebattery. By reducing the voltage drop, the battery's discharge-life timecan be extended before reaching the minimum battery voltage.

However, in the practical application of the aforementioned handhelddevices, electric motors, electric cars and the like, their batteriesare secondary batteries (such as lithium batteries). In addition toconsider the extension of the discharge-life time of the battery, infact, another important factor to be considered is the battery cyclelife. The circuit design of the PCT publication, WO01/89058A1, merelyconsiders the extension of the discharge-life time of the battery, butdoes not consider that the electricity quality is affected by thesecondary battery's dynamic response when using the secondary battery inpractice. Thus, the circuit design of the PCT publication, WO01/89058A1,does not consider the battery cycle life when using the secondarybattery in practice.

SUMMARY

An objective of the present disclosure is used to provide an energystorage system. In the present disclosure, the battery device composedof at least one secondary battery and the capacitor device composed ofat least one capacitor are electrically connected to each other inparallel, and by combining with the DC/DC converter (Direct Current toDirect Current converter), configuring the relation between theequivalent series resistor of the capacitor device and the internalresistor of the battery device, and/or configuring the upper currentlimit of the rated current of range the DC/DC converter, the batterycycle life of the secondary battery is increased.

To achieve the above objective, the present disclosure provides anenergy storage system, at least comprising: a battery device, having aninternal resistor; a first terminal and a second terminal, wherein thefirst terminal and the second terminal are respectively connected to twoelectrodes of a battery device, and polarities of the two electrodes ofthe battery device are opposite to each other; a capacitor device,electrically connected to the first terminal and the second terminal inparallel, and the capacitor device has an equivalent series resistor;and a DC/DC converter, electrically connected between the first terminaland the capacitor device; wherein a resistance of the equivalent seriesresistor is larger than that of the internal resistor.

In one embodiment of the present disclosure, the energy storage systemfurther comprises a third terminal, and the third terminal iselectrically connected between the DC/DC converter and the capacitordevice.

In one embodiment of the present disclosure, the third terminal is usedto provide electricity from the capacitor device to a load.

In one embodiment of the present disclosure, the third terminal is usedto provide electricity from an external power to the battery device.

In one embodiment of the present disclosure, the battery device is asecondary battery or formed by connecting secondary batteries inparallel or in series.

In one embodiment of the present disclosure, the capacitor device is acapacitor or formed by connecting capacitors in parallel or in series.The capacitor can be a super capacitor, multilayer ceramic capacitor,tantalum capacitor or electrolytic capacitor, and the present disclosureis not limited thereto.

In one embodiment of the present disclosure, the DC/DC converter has arated current range, the rated current range has an upper current limitand a lower current limit, the equivalent series resistor of thecapacitor device has a lower resistance limit, the lower resistancelimit is calculated and obtained according to the upper current limit,and the resistance of the equivalent series resistor is not less thanthe lower resistance limit.

The present disclosure provides another one energy storage system, atleast comprising: a battery device, having an internal resistor; a firstterminal and a second terminal, wherein the first terminal and thesecond terminal are respectively connected to two electrodes of abattery device, and polarities of the two electrodes of the batterydevice are opposite to each other; a capacitor device, electricallyconnected to the first terminal and the second terminal in parallel, andthe capacitor device has an equivalent series resistor; and a DC/DCconverter, electrically connected between the first terminal and thecapacitor device, wherein the DC/DC converter has a rated current range,the rated current range has an upper current limit and a lower currentlimit; wherein a resistance of the equivalent series resistor of thecapacitor device is larger than or equal to a lower resistance limit,the lower resistance limit is calculated by using equation (1):

$\begin{matrix}{{V = {I\left( {\frac{\Delta t}{C} + R} \right)}};} & {{equation}\mspace{14mu}(1)}\end{matrix}$

wherein V is a rated voltage of the capacitor device, I is the uppercurrent limit of the DC/DC converter, C is a capacitance of thecapacitor device, Δt is a charging/discharging time of the capacitordevice, R is the lower resistance limit of the equivalent seriesresistor of the capacitor device.

The present disclosure provides at least one capacitor device asmentioned above.

The present disclosure utilizes the capacitor device to directlydecouple a transient voltage generated at the output end of the DC/DCconverter, such that the ripple current is smoother, the effect of thecircuit operation quality caused by the dynamic response of the batterydevice is reduced, and the output electricity is more stable.Accordingly, the cycle life of the battery device can be indirectlyextended, and the decline of the battery device can be suppressed.

BRIEF DESCRIPTIONS OF DRAWINGS

FIG. 1 is a schematic diagram of an implementation of an energy storagesystem according to an embodiment of the present disclosure.

FIG. 2 is a schematic diagram of an implementation of connecting anenergy storage system and an external power according to an embodimentof the present disclosure.

FIG. 3 is a schematic diagram of an implementation of switching anenergy storage system to connect with a load or an external power viatwo switches according to an embodiment of the present disclosure.

FIG. 4 is a schematic diagram showing charging/discharging cycle testresults of comparative example 1 and embodiment 1 of the energy storagesystem of the present disclosure.

FIG. 5 is a schematic diagram showing charging/discharging cycle testresults of comparative example 2 and embodiment 2 of the energy storagesystem of the present disclosure.

FIG. 6 is a schematic diagram showing charging/discharging cycle testresults of comparative example 3 and embodiment 3 of the energy storagesystem of the present disclosure.

FIG. 7 is a schematic diagram showing a structure of a capacitor deviceof an energy storage system according to a first embodiment of thepresent disclosure.

FIG. 8 is a schematic diagram of an implementation of connecting anenergy storage system and a capacitor device according to an embodimentof the present disclosure.

FIG. 9 is a schematic diagram showing a structure of a capacitor deviceof an energy storage system according to a second embodiment of thepresent disclosure.

FIG. 10A is a schematic diagram showing a structure of two seriallyconnected capacitor devices of an energy storage system according to asecond embodiment of the present disclosure.

FIG. 10B is a schematic diagram showing a structure of three seriallyconnected capacitor devices of an energy storage system according to asecond embodiment of the present disclosure.

FIG. 10C is a schematic diagram showing a structure of four seriallyconnected capacitor devices of an energy storage system according to asecond embodiment of the present disclosure.

FIG. 11A is a schematic diagram showing another one structure of twoserially connected capacitor devices of an energy storage systemaccording to a second embodiment of the present disclosure.

FIG. 11B is a schematic diagram showing another one structure of threeserially connected capacitor devices of an energy storage systemaccording to a second embodiment of the present disclosure.

FIG. 11C is a schematic diagram showing another one structure of fourserially connected capacitor devices of an energy storage systemaccording to a second embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In order to facilitate the examiner to understand the technicalfeatures, the contents and the advantages of the present disclosure, aswell as the efficacy that can be reached by the present disclosure, thepresent disclosure will now be described in detail with the drawings andthe form of expression of the embodiments. The drawings used are onlyfor illustration and support of the specification, and hence are notnecessarily accurate in scale and precise in configuration afterimplementation of the present disclosure. Therefore, it should not beinterpreted based upon the scale and the configuration on the drawingsto confine the scope of the rights claimed on the practicalimplementation of the present disclosure.

Firstly, as shown in FIG. 1, the energy storage system 100 of thepresent disclosure at least comprises a battery device 110, a firstterminal 120, a second terminal 130, a capacitor device 1 and a DC/DCconverter 140.

The battery device 110 has an internal resistor. The battery device 110is a secondary battery or formed by connecting secondary batteries inparallel or in series. Herein, the battery device 110 of the illustratedembodiment is one secondary battery for example, the battery device 110has two electrodes, and the two electrodes have polarities opposite toeach other, such as a positive electrode and a negative electrode. Inthe example that the battery device 110 is formed by connectingsecondary batteries in parallel or in series, an internal resistor ofthe battery device 110 is a total internal resistor calculated accordingto internal resistors of the secondary batteries connected in parallelor in series.

The first terminal 120 and the second terminal 130 are respectivelyelectrically connected to the two electrodes of the battery device 110,for example, the first terminal 120 is connected to the positiveelectrode of the battery device 110, and the second terminal 130 iselectrically connected to the negative electrode of the battery device110.

The capacitor device 1 is electrically connected to the first terminal120 and the second terminal 130 in parallel, and the capacitor device 1has an equivalent series resistor. That is, the capacitor device 1 isconnected to the battery device 110 in parallel, and the capacitordevice 1 and the battery device 110 are connected between the firstterminal 120 and the second terminal 130 in parallel. The capacitordevice 1 can be a capacitor or formed by connecting capacitors inparallel or in series. The capacitor can be a super capacitor,multilayer ceramic capacitor, tantalum capacitor or electrolyticcapacitor, and the present disclosure is not limited thereto. In theexample that the capacitor device 1 is formed by connecting capacitorsin parallel or in series, the equivalent series resistor of thecapacitor device 1 is a total equivalent series resistor calculatedaccording to the resistors of the capacitors connected in series or inparallel.

The DC/DC converter 140 is electrically between the first terminal 120and the capacitor device 1, the DC/DC converter 140 has a rated currentrange (or current rating), and the rated current range has an uppercurrent limit and a lower current limit, for example, the rated currentrange is 2 A through 0.2 A, the upper current limit is 2 A, and thelower current limit is 0.2 A. The DC/DC converter 140 can be a boostconverter or a buck converter.

The energy storage system 100 further comprises a third terminal 150,the third terminal 150 is electrically connected between the DC/DCconverter 140 and the capacitor device 1, and the third terminal 150 isused to provide the electricity to a load 160 from the capacitor device1, as shown in FIG. 1. Or alternatively, as shown in FIG. 2, the thirdterminal 150 is used to provide the electricity to the battery device110 from the external power 170 via the first terminal 120. Certainly,there are multiple devices connected between the first terminal 120 andthe second terminal 130 in parallel, as shown in FIG. 3, and twoswitches 180 in the energy storage system 100 are used to control thethird terminal 150 to provide the electricity to the load 160 from thecapacitor device 1 or to provide the electricity to the battery device110 from the external power 170 via the first terminal 120. It is notedthat, the load 160 is a load of a smart watch, smart glasses, phone,electronic lock, electric tooth brush, hand tool or electric car, andthe present disclosure is not limited thereto.

When operating in practice, the energy storage system 100 allows thecurrent to flow between the battery device 110 an the capacitor device 1in dual ways so as to charge and discharge the battery device 110, forexample, the bidirectional DC-DC converter is adopted. Further in theenergy storage system 100, the cycle number which the capacitor device 1can be charged and discharged is larger than the cycle number thebattery device 110 can be charged and discharged, thus the capacitordevice 1 and the battery device 110 in the energy storage system 100 areelectrically connected in parallel, so as to enhance the cycle life ofthe battery device 110. Further, when the electricity is provided to theload 160 from the capacitor device 1 via the third terminal 150 (seeFIG. 2), since the DC/DC converter 140 of the energy storage system 100is electrically connected between the first terminal 120 and thecapacitor device 1, the capacitor device 1 is able to decouple thetransient voltage generated by the output end of the DC/DC converter140. Therefore, the ripple current is smoother, the effect of thecircuit operation quality caused by the dynamic response of the batterydevice 110 is reduced, and the output electricity is more stable.Accordingly, the cycle life of the battery device 110 is indirectlyincreased, and the decline of the battery device 110 can be suppressed.Preferably, the resistance of the equivalent series resistor is largerthan that of the internal resistor. Specifically, the equivalent seriesresistor of the capacitor device 1 has a lower resistance limit, and thelower resistance limit is calculated according to the upper currentlimit, and the resistance of the equivalent series resistor is not lessthan the lower resistance limit. The lower resistance limit iscalculated based upon equation (1):

$\begin{matrix}{{V = {I\left( {\frac{\Delta t}{C} + R} \right)}};} & {{equation}\mspace{14mu}(1)}\end{matrix}$

wherein V is a rated voltage of the capacitor device, I is the uppercurrent limit of the DC/DC converter, C is a capacitance of thecapacitor device, Δt is a charging/discharging time of the capacitordevice, R is the lower resistance limit of the equivalent seriesresistor of the capacitor device.

The analysis method of the cycle life:

In embodiments 1 through 3 and comparative examples 1 through 3,charging and discharging cycles of lithium batteries are tested in thefollowing condition: a constant current-constant voltage (CCCV) chargingmode and a constant power discharging mode are used, wherein the cut-offvoltage of charging is 5 volts, a charging current is 2 A, a cut-offvoltage of discharging is 2.8 volts and a discharging current is 2 A.The cycle life is defined as the cycle number which the tested lithiumbattery can be charged and discharged before the capacitance of thelithium battery drops to 80% of the original capacitance of the lithiumbattery. It is noted that, embodiments 1 through 3 utilize thearchitecture of the energy storage system 100, and comparative examples1 through 3 utilize the architecture of the energy storage system 100which the capacitor device 1 is removed therefrom. In other words, thedifferences between the embodiments 1 through 3 and comparative examples1 through 3 are the existence of the capacitor device 1.

Analysis result of the cycle life:

Test results of cycle life in embodiment 1 and comparative example 1:the battery device 110 in embodiment 1 and comparative example 1 is alithium polymer battery of Sanyo UF515761ST, which has a rated voltagebeing 3.7 volts, a rated capacity being 2600 mAh and an internalresistor being less than 38 mΩ; the upper current limit of the DC/DCconverter 140 is 2 A; the capacitor device 1 is selected as follows: thelower resistance limit R of the equivalent series resistor of thecapacitor device 1 is calculated based upon equation (1), wherein therated voltage V of the capacitor device 1 is 5.0 volts, the uppercurrent limit I of the DC/DC converter 140 is 2 A, the capacitance C ofthe capacitor device 1 is 80 mF, the charging/discharging time Δt of thecapacitor device 1 is 10 ms, and after equation (1) is calculated, thelower resistance limit R of the equivalent series resistor of thecapacitor device 1 is 2.375Ω, and thus the capacitor device 1 which hasthe equivalent series resistor being 2.375Ω is selected. It is notedthat the resistance of the equivalent series resistor (being 2.375Ω) islarger than that of the internal resistor (being less than 38 mΩ). Thetest results are: when the capacitance of the lithium polymer battery ofSanyo UF515761ST drops 80% of the original capacitance (see the Y axisin FIG. 4, the Y axis marked with “−20%” means the 20% loss of thecapacitance), the cycle number of embodiment 1 is 690 times, the cyclenumber of comparative example 1 is 240 times, and thus, by using theenergy storage system 100, the cycle life of the lithium polymer batteryof Sanyo UF515761ST is increased to 2.875 times (i.e. 690/240), as shownin FIG. 4. In addition, for the 245^(th) cycle, the capacitance loss ofembodiment 1 is merely 4.9%, and the capacitance loss of comparativeexample 1 is 19.5%. Accordingly, by using the energy storage system 100,the cycle life of the lithium polymer battery of Sanyo UF515761ST isenhanced as well as the operation time.

Test results of cycle life in embodiment 2 and comparative example 2:the battery device 110 in embodiment 2 and comparative example 2 is alithium polymer battery of LG ICP3339105L1, which has a rated voltagebeing 3.7 volts, a rated capacity being 2060 mAh and an internalresistor being equal to or less than 30 mΩ; the upper current limit ofthe DC/DC converter 140 is 2A; the capacitor device 1 is selected asfollows: the lower resistance limit R of the equivalent series resistorof the capacitor device 1 is calculated based upon equation (1), whereinthe rated voltage V of the capacitor device 1 is 5.0 volts, the uppercurrent limit I of the DC/DC converter 140 is 2 A, the capacitance C ofthe capacitor device 1 is 80 mF, the charging/discharging time Δt of thecapacitor device 1 is 10 ms, and after equation (1) is calculated, thelower resistance limit R of the equivalent series resistor of thecapacitor device 1 is 2.375Ω, and thus the capacitor device 1 which hasthe equivalent series resistor being 2.375Ω is selected. It is notedthat the resistance of the equivalent series resistor (being 2.375Ω) islarger than that of the internal resistor (being less than or equal to30 mΩ). The test results are: when the capacitance of the lithiumpolymer battery of LG ICP3339105L1 drops 80% of the original capacitance(see the Y axis in FIG. 5, the Y axis marked with “−20%” means the 20%loss of the capacitance), the cycle number of embodiment 2 is more than1000 times, the cycle number of comparative example 2 is about 500times, and thus, by using the energy storage system 100, the cycle lifeof the lithium polymer battery of Sanyo LG ICP3339105L1 is increased to2 times (i.e. 1000/500), as shown in FIG. 5.

Test results of cycle life in embodiment 3 and comparative example 3:the battery device 110 in in embodiment 3 and comparative example 3 is alithium ion battery of Maxell ICP575673, which has a rated voltage being3.8 volts, a rated capacity being 3100 mAh and an internal resistorbeing equal to or less than 70 mSΩ; the upper current limit of the DC/DCconverter 140 is 2 A; the capacitor device 1 is selected as follows: thelower resistance limit R of the equivalent series resistor of thecapacitor device 1 is calculated based upon equation (1), wherein therated voltage V of the capacitor device 1 is 5.0 volts, the uppercurrent limit I of the DC/DC converter 140 is 2 A, the capacitance C ofthe capacitor device 1 is 80 mF, the charging/discharging time Δt of thecapacitor device 1 is 10 ms, and after equation (1) is calculated, thelower resistance limit R of the equivalent series resistor of thecapacitor device 1 is 2.375Ω, and thus the capacitor device 1 which hasthe equivalent series resistor being 2.375Ω is selected. It is notedthat the resistance of the equivalent series resistor (being 2.375Ω) islarger than that of the internal resistor (being less than or equal to70 mΩ). The test manner is: after the lithium ion battery of MaxellICP575673 in comparative example 3 is charged and discharged 200 times,and then the lithium ion battery of Maxell ICP575673 of embodiment 3 ischarged and discharged 200 time again by using the energy storage system100, in other words, the lithium ion battery of Maxell ICP575673 beingcharged and discharged 200 times is the battery device 110 in embodiment3, and the battery device 110 in embodiment 3 is charged and discharged200 time again. The test results are: the lithium ion battery of MaxellICP575673 in comparative example 3 has a decline rate A being 12.3%, asshown in FIG. 6; however, the lithium ion battery of Maxell ICP575673 inembodiment 3 has a decline rate A merely being 2.3%. Thus, by using theenergy storage system 100 of embodiment 3, the decline of the capacityof the lithium ion battery of Maxell ICP575673 (battery device 110) canbe obviously suppressed.

Accordingly, by connecting the battery device 100 composed of the atleast one secondary battery and the capacitor device 1 in parallel,combining the DC/DC converter 140 in the energy storage system 100,configuring the relation of the equivalent series resistor and theinternal resistor, and or configuring the relation of the equivalentseries resistor and the upper current limit, the battery cycle life ofthe secondary battery is indeed extended.

Manufacturing of the Capacitor Device 1:

Refer to FIG. 7, and the capacitor device 1 of the first embodimentcomprises a first capacitor 10, a second capacitor 20, a third capacitor30 and a fourth capacitor 40.

The first capacitor 10 has first electrode 11, a second electrodel2, afirst electrolyte layer 13 and a first encapsulation bodyl4, wherein thesecond electrode 12 is disposed opposite to the first electrode 11, thefirst electrolyte layer 13 is disposed between the first electrode 11and the second electrode 12, and the first encapsulation body 14encapsulates the first electrode 11, the second electrode 12 and thefirst electrolyte layer 13.

The second capacitor 20 has a third electrode 21, a fourth electrode 22,a second electrolyte layer 23 and a second encapsulation body 24,wherein the fourth electrode 22 is disposed opposite to the thirdelectrode 21, the second electrolyte layer 23 is disposed between thethird electrode 21 and the fourth electrode 22, and the secondencapsulation body 24 encapsulates the third electrode 21, the fourthelectrode 22 and the second electrolyte layer 23.

The third capacitor 30 has a fifth electrode 31, a sixth electrode 32, athird electrolyte layer 33 and a third encapsulation body 34, whereinthe sixth electrode 32 is disposed opposite to the fifth electrode 31,the third electrolyte layer 33 is disposed between the fifth electrode31 and the sixth electrode 32, and the third encapsulation body 34encapsulates the fifth electrode 31, the sixth electrode 32 and thethird electrolyte layer 33.

The fourth capacitor 40 has a seventh electrode 41, an eighth electrode42, a fourth electrolyte layer 43 and a fourth encapsulation body 44,wherein the eighth electrode 42 is disposed opposite to the seventhelectrode 41, the fourth electrolyte layer 43 is disposed between theseventh electrode 41 and the eighth electrode 42, and the fourthencapsulation body 44 encapsulates the seventh electrode 41, the eighthelectrode 42 and the fourth electrolyte layer 43.

The first electrode 11 and the third electrode 21 are integrally formed,the fifth electrode 31 and the seventh electrode 41 are integrallyformed, the second electrode 12 and the sixth electrode 32 areintegrally formed, and the fourth electrode 22 and the eighth electrode42 are integrally formed. The second electrode 12 and the fourthelectrode 22 are electrically insulated from each other. The firstelectrolyte layer 13, the second electrolyte layer 23, the thirdelectrolyte layer 33 and the fourth electrolyte layer 43 are independentto each other without contacting. It is noted that the term “formedintegrally” (or called “integrated molding”) means “formed by the sameprocess without assembly”. For example, “the first electrode 11 and thethird electrode 21 are formed integrally” means “the first electrode 11and the third electrode 21 are formed by cutting an electrode plate to apredetermined shape (such as, rectangular sheet)”. Thus, the firstelectrode 11 and the third electrode 21 are formed by the same electrodeplate processed with a cutting process, and have the integrity of theintegrated molding. The term “without assembly” means the two electrodeplates are not combined via welding, bonding or one of other manners.For example, the first electrode 11 and the third electrode 21 areintegrally formed without welding or adhesion of conducting glue.

The capacitor device 1 further has a first lead electrode P1 and asecond lead electrode P2, the first lead electrode P1 is electricallyconnected to the second electrode 12, and the second lead electrode P2is electrically connected to the fourth electrode 22. Preferably, thefirst lead electrode P1 and the second electrode 12 are formedintegrally, and the second lead electrode P2 and the fourth electrode 22are formed integrally.

The first electrode 11, the second electrode 12, the third electrode 21,the fourth electrode 22, the fifth electrode 31, the sixth electrode 32,the seventh electrode 41, the eighth electrode 42, the first leadelectrode P1 and the second lead electrode P2 are made of conductivematerial which has electron conducting ability. Each of them can beindependent metal foil, metal plate, metal mesh, activated carbon coatedmetal mesh, activated carbon coated metal sheet, activated carbon coatedmetal foil, activated carbon cloth, activated carbon fiber, metalcomposite mesh, metal composite sheet, transition metal oxide layer orplate made of transition metal oxide, or conductive polymer layer madeof conductive polymer. Preferably, the first electrode 11, the secondelectrode 12, the third electrode 21, the fourth electrode 22, the fifthelectrode 31, the sixth electrode 32, the seventh electrode 41, theeighth electrode 42, the first lead electrode P1 and the second leadelectrode P2 can be nickel metal foils. More preferably, the firstelectrode 11, the second electrode 12, the third electrode 21, thefourth electrode 22, the fifth electrode 31, the sixth electrode 32, theseventh electrode 41, the eighth electrode 42, the first lead electrodeP1 and the second lead electrode P2 can be nickel metal foils whichsurfaces are coated with activated carbon layers.

The first electrolyte layer 13, the second electrolyte layer 23, thethird electrolyte layer 33 and the fourth electrolyte layer 43 areelectrolyte layers composed of the electrolytes, and preferably, theaqueous electrolyte layers composed of aqueous electrolytes. The aqueouselectrolyte is, for example, an aqueous solution of lithium, sodium,potassium salts, or any combination thereof.

The first encapsulation body 14, the second encapsulation body 24, thethird encapsulation body 34 and the fourth encapsulation body 44 areinsulation layers made of insulation material, and the insulationmaterial preferably has the characteristics of resistance to acid andalkali, high waterproof and gas permeation resistance, such as glue orthermosetting epoxy molding compound (EMC).

Interior of the first electrolyte layer 13 can be disposed with a firstisolation film 15 having an ion conduction ability, interior of thesecond electrolyte layer 23 can be disposed with a second isolation film25 having an ion conduction ability, interior of the third electrolytelayer 33 can be disposed with a third isolation film 35 having an ionconduction ability, and interior of the fourth electrolyte layer 43 canbe disposed with a fourth isolation film 45 having an ion conductionability. The first isolation film 15, the second isolation film 25, thethird isolation film 35 and the fourth isolation film 45 can be acellulose film, single or multiple layers of polypropylene (PP) film,polyethylene (PE) film, polytetrafluoroethene (PTFE) film,polyvinylidene fluoride (PVDF) Film or a composite film of anycombination of the above. It is noted that, when the electrolyte is thesolid electrolyte or spacers are inserted, the first isolation film 15,the second isolation film 25, the third isolation film 35 and the fourthisolation film 45 can be removed. The spacers can be ribs, for example,which are disposed between electrodes with gaps therebetween.

When the capacitor device 1 is electrically connected to the batterydevice 110 in parallel, the first lead electrode P1 and the secondterminal 130 are electrically connected to each other, and the secondlead electrode P2 is electrically connected to the third terminal 150,so as to charge the battery device 110, as shown in FIG. 8. Refer toFIG. 7 and FIG. 8, in the case of charging, the first lead electrode P1,the second electrode 12, the sixth electrode 32, the third electrode 21and the seventh electrode 41 have the same electrode polarity (such as,the polarity of the negative electrode), and the second lead electrodeP2, the fourth electrode 22, the eighth electrode 42, the firstelectrode 11 and the fifth electrode 31 have the other same electrodepolarity (such as, the polarity of the positive electrode.

When the capacitor device 1 and the load 160 are connected fordischarging, the first lead electrode P1, the second electrode 12, thesixth electrode 32, the third electrode 21 and the seventh electrode 41the same electrode polarity (such as, the polarity of the negativeelectrode), the second lead electrode P2, the fourth electrode 22, theeighth electrode 42, the first electrode 11 and the fifth electrode 31have the other same electrode polarity (such as, the polarity of thepositive electrode.

When the capacitor device 1 is charged or discharged, since the firstelectrode 11 of the first capacitor 10 and the third electrode 21 of thesecond capacitor 20 are formed integrally, the first capacitor 10 andthe second capacitor 20 are connected in series; and since the thirdelectrode 31 of the third capacitor 30 and the seventh electrode 41 ofthe fifth electrode 31 are formed integrally, the third capacitor 30 andthe fourth capacitor 40 are formed integrally. Accordingly, thecapacitor device 1 has a high voltage by using the serial connection.

When charging or discharging the capacitor device 1, since the secondelectrode 12 of the first capacitor 10 and the sixth electrode 32 of thethird capacitor 30 are formed integrally, the first capacitor 10 andthird capacitor 30 are connected in parallel, and since the fourthelectrode 22 of the second capacitor 20 and the eighth electrode 42 ofthe fourth capacitor 40 are formed integrally, the second capacitor 20and fourth capacitor 40 are connected in parallel, which results a highcapacitance of the capacitor device by using such parallel connection,

It is noted that, the first capacitor 10, the second capacitor 20, thethird capacitor 30 and the fourth capacitor 40 can be independent supercapacitors. The first encapsulation body 14, the second encapsulationbody 24, the third encapsulation body 34 and the fourth encapsulationbody 44 are independently insulated from the first electrode 11, thesecond electrode 12, the third electrode 21, the fourth electrode 22,the fifth electrode 31, the sixth electrode 32, the seventh electrode41, the eighth electrode 42, the first lead electrode P1 and the secondlead electrode P2. For example, the first capacitor 10, the secondcapacitor 20, the third capacitor 30 and the fourth capacitor 40 have Avolts and B farads, and since the first capacitor 10 and the secondcapacitor 20 are connected in series, the third capacitor 30 and thefourth capacitor 40 are connected in parallel, the capacitor device 1has a high voltage of 2A volts. Since the first capacitor 10 and thethird capacitor 30 are connected in series, and the second capacitor 20and the fourth capacitor 40 are connected in parallel, the capacitordevice 1 has a high capacitance of 2 B farads. In addition, preferably,the first encapsulation body 14, the second encapsulation body 24, thethird encapsulation body 34 and the fourth encapsulation body 44 areformed integrally, and thus in the interior of the capacitor device 1,the serial and parallel connections of the first capacitor 10, thesecond capacitor 20, the third capacitor 30 and the fourth capacitor 40are formed.

It is noted that, the capacitor device 1 has at least one commonelectrode, and the common electrode means a same electrode plateutilized between at least two capacitors, and each of a top surface anda bottom surface of the common electrode forms at least one capacitor.That is, a top and bottom surface of the common electrode thus can beutilized at the same time, which is not like the conventional electrodewhich one of a top surface and a bottom surface is merely utilized.Therefore, the capacitor device utilizing the common electrode can beused to save the electrode material and decrease the whole thickness,which is helpful to miniaturization of the capacitor device 1. Forexample, the capacitor device 1 has two common electrodes C1 and C2. Thesecond electrode 12 of the first capacitor 10 and the sixth electrode 32of the third capacitor 30 are formed integrally, i.e. the secondelectrode 12 and the sixth electrode 32 are formed by the same electrodeplate which is the common electrode C1 of the first capacitor 10 and thethird capacitor 30, and the top surface and the bottom surface of thecommon electrode C1 respectively form the first capacitor 10 and thethird capacitor 30. The fourth electrode 22 of the second capacitor 20and the eighth electrode 42 of the fourth capacitor 40 are formedintegrally, i.e. the fourth electrode 22 and the eighth electrode 42 areformed by the same electrode plate which is the common electrode C2 ofthe second capacitor 20 and the fourth capacitor 40, and the top surfaceand the bottom surface of the common electrode C2 respectively form thesecond capacitor 20 and the fourth capacitor 40. Specifically, the fourcapacitors are divided into two sets, two capacitors of each set areconnected in parallel, the conventional manner has total four electrodesurfaces which cannot be utilized in capacitor formation and this causeswastes, and the capacitor device formed by the capacitors has athickness larger than a double thickness of the capacitor (for example,the two capacitors of each set are stacked and connected in parallel).However, by using the common electrode of the present disclosure, thetop surface and the bottom surface of the common electrode (such as, thecommon electrode C1) form the capacitors (such as, the first capacitor10 and the third capacitor 30), and the common electrode can be fullyutilized without wastes. Further, the present disclosure has anunexpected result, since the thickness of the common electrode is thethickness of the single one capacitor (the thickness of the commonelectrode C1 of FIG. 2), the capacitor device in the present disclosurehas a thickness less than a half thickness of the conventional capacitordevice, which meets the requirement of miniaturization.

Refer to FIG. 9 which illustrates a second embodiment of the capacitordevice 1, the capacitor device 1 in the second embodiment is similar tothe capacitor device 1 in the first embodiment, and same parts are notdescribed again. The capacitor devices 1 in the first and secondembodiments have the difference as follows: in the second embodiment,the second electrode 12, the fourth electrode 22, the sixth electrode 32and the eighth electrode 42 of the capacitor device 1 are formedintegrally, and first electrode 11 is electrically insulated from thethird electrode 21, the fifth electrode 31 is electrically insulatedfrom the seventh electrode 41, the first lead electrode P1 iselectrically connected to the first electrode 11 and the fifth electrode31, and the second lead electrode P2 is electrically connected to thethird electrode 21 and the seventh electrode 41. Preferably, the firstlead electrode P1, the first electrode 11 and the fifth electrode 31 areformed integrally, and the second lead electrode P2, the third electrode21 and the seventh electrode 41 are formed integrally.

It is noted that, in the second embodiment, the capacitor device 1 has acommon electrode C3. Since the second electrode 12, the fourth electrode22, the sixth electrode 32 and the eighth electrode 42 are formedintegrally, i.e. the second electrode 12, the fourth electrode 22, thesixth electrode 32 and the eighth electrode 42 are formed by the sameelectrode plate which is the common electrode C3 of the first capacitor10, the second capacitor 20, the third capacitor 30 and the fourthcapacitor 40, a left end and a right end of a top surface of the commonelectrode C3 respectively form the first capacitor 10 and the secondcapacitor 20, and a left end and a right end of a bottom surface of thecommon electrode C3 respectively form the third capacitor 30 and thefourth capacitor 40. By designing the common electrode C3 to be thecommon electrode of the first capacitor 10, the second capacitor 20, thethird capacitor 30 and the fourth capacitor 40, it has the unexpectedresult as follows: compared to the conventional electrode which usesmerely one of the top surface and the bottom surface of the electrode,the capacitor device 1 can save the electrode material, decrease thewhole thickness and meet the requirement of miniaturization of thecapacitor device 1.

When the capacitor device 1 in the second embodiment is charged ordischarged, the first lead electrode P1, the first electrode 11, thefifth electrode 31, the fourth electrode 22 and the eighth electrode 42have the same electrode polarity (such as, the polarity of the negativeelectrode), and the second lead electrode P2, the third electrode 21,the seventh electrode 41, the second electrode 12 and the sixthelectrode 32 have the other same electrode polarity (such as, thepolarity of the positive electrode). Since the second electrode 12 ofthe first capacitor 10 and the fourth electrode 22 of the secondcapacitor 20 are formed integrally, the first capacitor 10 and thesecond capacitor 20 are connected in series, and since the sixthelectrode 32 of the third capacitor 30 and the eighth electrode 42 ofthe sixth electrode 32 are formed integrally, the third capacitor 30 andthe fourth capacitor 40 are connected in series. Therefore, thecapacitor device 1 has a high voltage by using the serial connection.Since the second electrode 12 of the first capacitor 10 and the sixthelectrode 32 of the third capacitor 30 are formed integrally, the firstcapacitor 10 and the third capacitor 30 are connected in parallel, andsince the fourth electrode of the second capacitor 20 and the eighthelectrode 42 of the fourth capacitor 40 are formed integrally, thesecond capacitor 20 and the fourth capacitor 40 are connected inparallel. Therefore, the capacitor device 1 has a high capacitance byusing the parallel connection. It is noted that, since the secondelectrode 12, the sixth electrode 32, the fourth electrode 22 and theeighth electrode 42 are formed integrally, the serial and parallelconnections can be formed at the same time. Therefore, in the interiorof the capacitor device 1, the serial and parallel connections of thefirst capacitor 10, the second capacitor 20, the third capacitor 30 andthe fourth capacitor 40 are formed.

In the above first and second embodiments, twos of the first capacitor10, the second capacitor 20, the third capacitor 30 and the fourthcapacitor 40 in the capacitor device 1 are connected in series, andother twos are connected in parallel. If the first capacitor 10, thesecond capacitor 20, the third capacitor 30 and the fourth capacitor 40in the capacitor device 1 have the same voltage and capacitance, thecapacitor device 1 has the voltage of 2 A volts and the capacitance of 2B farads.

Refer to FIG. 10A through FIG. 10C, in the present disclosure, thecapacitor devices 1 in the first embodiment are connected in series,wherein the fourth electrode 22 and the eighth electrode 42 of thecapacitor device 1, and the second electrode 12 and the sixth electrode32 of other adjacent capacitor device 1 are formed integrally. In otherwords, the fourth electrode 22 and the eighth electrode 42 in thecapacitor device 1, and the second electrode 12 and the sixth electrode32 of other adjacent capacitor device 1 are formed by the same electrodeplate which is the common electrode C4 of the two adjacent capacitordevices 1 (see FIG. 10A). Thus, the capacitor devices 1 are linearlyarranged and the adjacent capacitor devices 1 are connected in series,which can achieve the preset voltage and the preset capacitance. The twocapacitor devices 1 in FIG. 10A are connected in series, and thus theequivalent voltage and capacitance are 4 A volts and 2 B farads. Thethree capacitor devices 1 in FIG. 10B are connected in series, and thusthe equivalent voltage and capacitance are 6 A volts and 2 B farads. Thefour capacitor devices 1 in FIG. 10C are connected in series, and thusthe equivalent voltage and capacitance are 8 A volts and 2 B farads. Itis obvious that the more the capacitor devices 1 are connected inseries, the more significant the saving effect of utilizing the topsurface and the bottom surface of the common electrode can be achieved.

Refer to FIG. 11A through 11C, the capacitor devices 1 in the secondembodiment are connected in series, i.e. the capacitor devices 1 arearranged linearly and connected in series. The third electrode 21 andthe seventh electrode 41 of the capacitor device 1, and the firstelectrode 11 and the fifth electrode 31 of another adjacent capacitordevice 1 are formed integrally. In other words, the third electrode 21and the seventh electrode 41 of the capacitor device 1, and the firstelectrode 11 and the fifth electrode 31 of other adjacent capacitordevice 1 are formed by the same electrode plate which is the commonelectrode C5 of the two adjacent capacitor devices 1 (as shown in FIG.11A). The seventh electrode 41 of the capacitor device 1 and the fifthelectrode 31 of the other adjacent capacitor device 1 are formed by thesame electrode plate which is the common electrode C6 of the twoadjacent capacitor devices 1 (as shown in FIG. 11A). Thus, the capacitordevices 1 are connected in series, which can achieve the preset voltageand the preset capacitance. The two capacitor devices 1 in FIG. 11A areconnected in series, and thus the equivalent voltage and capacitance are4 A volts and 2 B farads. The three capacitor devices 1 in FIG. 11B areconnected in series, and thus the equivalent voltage and capacitance are6 A volts and 2 B farads. The four capacitor devices 1 in FIG. 11C areconnected in series, and thus the equivalent voltage and capacitance are8 A volts and 2 B farads. Similarly, the more the capacitor devices 1are connected in series, the more significant the saving effect ofutilizing the top surface and the bottom surface of the common electrodecan be achieved.

According to the descriptions of the above embodiments, compared to theprior art and the conventional product, the battery device composed ofthe at least one secondary battery and the capacitor device composed ofthe at least one capacitor in the energy storage system of the presentdisclosure are connected in parallel, the DC/DC converter is combinedwith the battery device and the capacitor device, the resistance of theequivalent series resistor is configured to be larger than that of theinternal resistor, and/or the resistance of the equivalent seriesresistor is configured to be not less than the lower resistance limitwhich is calculated according to the upper current limit of the ratedcurrent range of the DC/DC converter, such that the battery cycle lifeof the secondary battery is increased.

In summary, the energy storage system of the present invention canindeed achieve the expected effect through the embodiments disclosedabove, and the energy storage system has not been disclosed before thepresent disclosure is filed. The present disclosure has been fullycomplied with the requirements and regulations of the patent law, thusthe present disclosure is filed accordance with the patent law, andallowance of claims of the present disclosure is respectfully requested.

The above-mentioned descriptions represent merely the exemplaryembodiment of the present disclosure, without any intention to limit thescope of the present disclosure thereto. Various equivalent changes,alternations or modifications based on the claims of present disclosureare all consequently viewed as being embraced by the scope of thepresent disclosure.

1. A capacitor device, at least comprising: a first capacitor, having afirst electrode, a second electrode, a first electrolyte layer and afirst encapsulation body, wherein the second electrode is disposedopposite to the first electrode, the first electrolyte layer is disposedbetween the first electrode and the second electrode, and the firstencapsulation body encapsulates the first electrode, the secondelectrode and the first electrolyte layer; a second capacitor, having athird electrode, a fourth electrode, a second electrolyte layer and asecond encapsulation body, wherein the fourth electrode is disposedopposite to the third electrode, the second electrolyte layer isdisposed between the third electrode and the fourth electrode, and thesecond encapsulation body encapsulates the third electrode, the fourthelectrode and the second electrolyte layer; a third capacitor, having afifth electrode, a sixth electrode, a third electrolyte layer and athird encapsulation body, wherein the sixth electrode is disposedopposite to the fifth electrode, the third electrolyte layer is disposedbetween the fifth electrode and the sixth electrode, and the thirdencapsulation body encapsulates the fifth electrode, the sixth electrodeand the third electrolyte layer; and a fourth capacitor, having aseventh electrode, an eighth electrode, a fourth electrolyte layer and afourth encapsulation body, wherein the eighth electrode is disposedopposite to the seventh electrode, the fourth electrolyte layer isdisposed between the seventh electrode and the eighth electrode, and thefourth encapsulation body encapsulates the seventh electrode, the eighthelectrode and the fourth electrolyte layer; wherein the first electrodeand the third electrode are integrally formed, the fifth electrode andthe seventh electrode are integrally formed, the second electrode andthe sixth electrode are integrally formed, and the fourth electrode andthe eighth electrode are integrally formed; the second electrode and thefourth electrode are electrically insulated from each other; thecapacitor device further has a first lead electrode and a second leadelectrode, the first lead electrode and the second electrode areelectrically connected to each other, the second lead electrode and thefourth electrode are electrically connected to each other.
 2. Thecapacitor device according to claim 1, wherein the second electrode andthe sixth electrode are formed by a first electrode plate, and acted asa first common electrode of the first capacitor and the third capacitor,and a top surface and a bottom surface of the first common electroderespectively form the first capacitor and the third capacitor.
 3. Thecapacitor device according to claim 2, wherein the fourth electrode andthe eighth electrode are formed by a second electrode plate, and actedas a second common electrode of the second capacitor and the fourthcapacitor, and a top surface and a bottom surface of the second commonelectrode respectively form the second capacitor and the fourthcapacitor.
 4. A capacitor device, at least comprising: a firstcapacitor, having a first electrode, a second electrode, a firstelectrolyte layer and a first encapsulation body, wherein the secondelectrode is disposed opposite to the first electrode, the firstelectrolyte layer is disposed between the first electrode and the secondelectrode, and the first encapsulation body encapsulates the firstelectrode, the second electrode and the first electrolyte layer; asecond capacitor, having a third electrode, a fourth electrode, a secondelectrolyte layer and a second encapsulation body, wherein the fourthelectrode is disposed opposite to the third electrode, the secondelectrolyte layer is disposed between the third electrode and the fourthelectrode, and the second encapsulation body encapsulates the thirdelectrode, the fourth electrode and the second electrolyte layer; athird capacitor, having a fifth electrode, a sixth electrode, a thirdelectrolyte layer and a third encapsulation body, wherein the sixthelectrode is disposed opposite to the fifth electrode, the thirdelectrolyte layer is disposed between the fifth electrode and the sixthelectrode, and the third encapsulation body encapsulates the fifthelectrode, the sixth electrode and the third electrolyte layer; and afourth capacitor, having a seventh electrode, an eighth electrode, afourth electrolyte layer and a fourth encapsulation body, wherein theeighth electrode is disposed opposite to the seventh electrode, thefourth electrolyte layer is disposed between the seventh electrode andthe eighth electrode, and the fourth encapsulation body encapsulates theseventh electrode, the eighth electrode and the fourth electrolytelayer; wherein the second electrode, the fourth electrode, the sixthelectrode and the eighth electrode are integrally formed, the firstelectrode and the third electrode are electrically insulated from eachother, and the fifth electrode and the seventh electrode areelectrically insulated from each other; the capacitor device further hasa first lead electrode and a second lead electrode, the first leadelectrode is electrically connected to the first electrode and the fifthelectrode, the second lead electrode is electrically connected to thirdelectrode and the seventh electrode.
 5. The capacitor device accordingto claim 4, wherein the second electrode, the fourth electrode, thesixth electrode and the eighth electrode are formed by an electrodeplate, and acted as a common electrode of the first capacitor, thesecond capacitor, the third capacitor and the fourth capacitor, a leftend and a right end of a top surface of the common electroderespectively form the first capacitor and the second capacitor, and aleft end and a right end of a bottom surface of the common electroderespectively form the third capacitor and the fourth capacitor.